(CNN) -- Immigration reform returned to the U.S. political arena in 2010, three years after it was knocked down by a much-debated Senate vote. The issue drew national outrage and support after Arizona enacted a state law that allows police to ask for proof of legal U.S. residency.

The law initially allowed police to ask anyone for proof of legal U.S. residency, based solely on a police officer's suspicion that the person might be in the country illegally. Arizona lawmakers soon amended the law so that officers could check a person's status only if the person had been stopped or arrested for another reason.

Arizona's Republican Gov. Jan Brewer, who's locked in a competitive re-election campaign, signed the bill into law and revived an intense national debate on what to do about illegal Mexican immigrants and undocumented workers in the United States.

The law has become an issue in a competitive primary race for U.S. Senate as Republican Sen. John McCain fights to continue representing Arizona on Capitol Hill.

McCain co-sponsored the 2007 Senate immigration reform bill, which called for tightening border security and creating a path to citizenship for some of the nation's 12 million illegal immigrants. But faced with a tough challenge by former Rep. J.D. Hayworth, McCain has reversed his position on offering citizenship to illegal immigrants.

The president has described as "promising" an immigration reform plan outlined by Sen. Charles Schumer, D-New York, and Sen. Lindsey Graham, R-South Carolina.

In a statement, the lawmakers said their plan includes "biometric Social Security cards to ensure that illegal workers cannot get jobs; fulfilling and strengthening our commitments on border security and interior enforcement; creating a process for admitting temporary workers; and implementing a tough but fair path to legalization" for illegal immigrants in the United States.

Calls for reform; troops to deploy along border

Reaction to the Arizona law prompted Obama to enter the fray, calling on Congress to begin work on a new immigration reform bill. The president, who called the law misguided,has also ordered 1,200 U.S. troops to deploy along the Mexican border.

The National Guard forces will help with drug enforcement and intelligence efforts until Customs and Border Protection can recruit and train additional officers and agents to serve on the border, an administration official said. McCain said the number fell short and called for 3,000 troops.

Reflecting their outrage about Arizona's new law, nearly 30 organizations have agreed to join an economic boycott of the state's $18.6 billion travel industry, including the Rev. Al Sharpton's National Action Network, People for the American Way, the Japanese American Citizens League and the Service Employees International Union.

Lawmakers from four other states have contacted the Immigration Reform Law Institute asking for help to draft language for bills like the Arizona bill. The group has declined to identify which states. The speaker of the Rhode Island House has said an Arizona copycat bill sponsored by a Democratic lawmaker will not be considered this session.